McMaster University — MedicalXPress, 10 February 2022
Scientists at McMaster University who have developed an inhaled form of COVID vaccine have confirmed it can provide broad, long-lasting protection against the original strain of SARS-CoV-2 and variants of concern. Because inhaled vaccines target the lungs and upper airways where respiratory viruses first enter the body, they are far more effective at inducing a protective immune response, the researchers report in the journal Cell.
The McMaster COVID vaccine targets three parts of the virus, including two that are highly conserved among coronaviruses and do not mutate as quickly as spike. All COVID vaccines currently approved in Canada target only the spike protein, which has shown a remarkable ability to mutate. Associate professor Matthew Miller explained: “We can remain ahead of the virus with our vaccine strategy. Current vaccines are limited because they will need to be updated and will always be chasing the virus.”
An inhaled vaccine is also so efficient at targeting the lungs and upper airways that it can achieve maximum protection with a small fraction of the dose of current vaccines — possibly as little as 1 percent — meaning a single batch of vaccine could go 100 times further. The vaccine also stimulates a unique form of immunity known as trained innate immunity, which is able to provide very broad protection against many lung pathogens besides SARS-CoV-2. A Phase 1 clinical trial evaluating inhaled aerosol vaccines in healthy adults who had already received two doses of a COVID mRNA vaccine is currently under way.